diff options
Diffstat (limited to 'drivers/iio/chemical/atlas-ezo-sensor.c')
| -rw-r--r-- | drivers/iio/chemical/atlas-ezo-sensor.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/iio/chemical/atlas-ezo-sensor.c b/drivers/iio/chemical/atlas-ezo-sensor.c new file mode 100644 index 000000000..b1bacfe3c --- /dev/null +++ b/drivers/iio/chemical/atlas-ezo-sensor.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * atlas-ezo-sensor.c - Support for Atlas Scientific EZO sensors + * + * Copyright (C) 2020 Konsulko Group + * Author: Matt Ranostay <matt.ranostay@konsulko.com> + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/mutex.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/of_device.h> +#include <linux/iio/iio.h> + +#define ATLAS_EZO_DRV_NAME "atlas-ezo-sensor" +#define ATLAS_INT_TIME_IN_MS 950 +#define ATLAS_INT_HUM_TIME_IN_MS 350 + +enum { + ATLAS_CO2_EZO, + ATLAS_O2_EZO, + ATLAS_HUM_EZO, +}; + +struct atlas_ezo_device { + const struct iio_chan_spec *channels; + int num_channels; + int delay; +}; + +struct atlas_ezo_data { + struct i2c_client *client; + struct atlas_ezo_device *chip; + + /* lock to avoid multiple concurrent read calls */ + struct mutex lock; + + u8 buffer[8]; +}; + +#define ATLAS_CONCENTRATION_CHANNEL(_modifier) \ + { \ + .type = IIO_CONCENTRATION, \ + .modified = 1,\ + .channel2 = _modifier, \ + .info_mask_separate = \ + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), \ + .scan_index = 0, \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 32, \ + .storagebits = 32, \ + .endianness = IIO_CPU, \ + }, \ + } + +static const struct iio_chan_spec atlas_co2_ezo_channels[] = { + ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_CO2), +}; + +static const struct iio_chan_spec atlas_o2_ezo_channels[] = { + ATLAS_CONCENTRATION_CHANNEL(IIO_MOD_O2), +}; + +static const struct iio_chan_spec atlas_hum_ezo_channels[] = { + { + .type = IIO_HUMIDITYRELATIVE, + .info_mask_separate = + BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, +}; + +static struct atlas_ezo_device atlas_ezo_devices[] = { + [ATLAS_CO2_EZO] = { + .channels = atlas_co2_ezo_channels, + .num_channels = 1, + .delay = ATLAS_INT_TIME_IN_MS, + }, + [ATLAS_O2_EZO] = { + .channels = atlas_o2_ezo_channels, + .num_channels = 1, + .delay = ATLAS_INT_TIME_IN_MS, + }, + [ATLAS_HUM_EZO] = { + .channels = atlas_hum_ezo_channels, + .num_channels = 1, + .delay = ATLAS_INT_HUM_TIME_IN_MS, + }, +}; + +static void atlas_ezo_sanitize(char *buf) +{ + char *ptr = strchr(buf, '.'); + + if (!ptr) + return; + + memmove(ptr, ptr + 1, strlen(ptr)); +} + +static int atlas_ezo_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct atlas_ezo_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + + if (chan->type != IIO_CONCENTRATION) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: { + int ret; + long tmp; + + mutex_lock(&data->lock); + + tmp = i2c_smbus_write_byte(client, 'R'); + + if (tmp < 0) { + mutex_unlock(&data->lock); + return tmp; + } + + msleep(data->chip->delay); + + tmp = i2c_master_recv(client, data->buffer, sizeof(data->buffer)); + + if (tmp < 0 || data->buffer[0] != 1) { + mutex_unlock(&data->lock); + return -EBUSY; + } + + /* removing floating point for fixed number representation */ + atlas_ezo_sanitize(data->buffer + 2); + + ret = kstrtol(data->buffer + 1, 10, &tmp); + + *val = tmp; + + mutex_unlock(&data->lock); + + return ret ? ret : IIO_VAL_INT; + } + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_HUMIDITYRELATIVE: + *val = 10; + return IIO_VAL_INT; + case IIO_CONCENTRATION: + break; + default: + return -EINVAL; + } + + /* IIO_CONCENTRATION modifiers */ + switch (chan->channel2) { + case IIO_MOD_CO2: + *val = 0; + *val2 = 100; /* 0.0001 */ + return IIO_VAL_INT_PLUS_MICRO; + case IIO_MOD_O2: + *val = 100; + return IIO_VAL_INT; + } + return -EINVAL; + } + + return 0; +} + +static const struct iio_info atlas_info = { + .read_raw = atlas_ezo_read_raw, +}; + +static const struct i2c_device_id atlas_ezo_id[] = { + { "atlas-co2-ezo", ATLAS_CO2_EZO }, + { "atlas-o2-ezo", ATLAS_O2_EZO }, + { "atlas-hum-ezo", ATLAS_HUM_EZO }, + {} +}; +MODULE_DEVICE_TABLE(i2c, atlas_ezo_id); + +static const struct of_device_id atlas_ezo_dt_ids[] = { + { .compatible = "atlas,co2-ezo", .data = (void *)ATLAS_CO2_EZO, }, + { .compatible = "atlas,o2-ezo", .data = (void *)ATLAS_O2_EZO, }, + { .compatible = "atlas,hum-ezo", .data = (void *)ATLAS_HUM_EZO, }, + {} +}; +MODULE_DEVICE_TABLE(of, atlas_ezo_dt_ids); + +static int atlas_ezo_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct atlas_ezo_data *data; + struct atlas_ezo_device *chip; + const struct of_device_id *of_id; + struct iio_dev *indio_dev; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + of_id = of_match_device(atlas_ezo_dt_ids, &client->dev); + if (!of_id) + chip = &atlas_ezo_devices[id->driver_data]; + else + chip = &atlas_ezo_devices[(unsigned long)of_id->data]; + + indio_dev->info = &atlas_info; + indio_dev->name = ATLAS_EZO_DRV_NAME; + indio_dev->channels = chip->channels; + indio_dev->num_channels = chip->num_channels; + indio_dev->modes = INDIO_DIRECT_MODE; + + data = iio_priv(indio_dev); + data->client = client; + data->chip = chip; + mutex_init(&data->lock); + + return devm_iio_device_register(&client->dev, indio_dev); +}; + +static struct i2c_driver atlas_ezo_driver = { + .driver = { + .name = ATLAS_EZO_DRV_NAME, + .of_match_table = atlas_ezo_dt_ids, + }, + .probe = atlas_ezo_probe, + .id_table = atlas_ezo_id, +}; +module_i2c_driver(atlas_ezo_driver); + +MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>"); +MODULE_DESCRIPTION("Atlas Scientific EZO sensors"); +MODULE_LICENSE("GPL"); |